I have a Slot A Classic 850 @ 950 with a GFD. I hard moddedthe cache divider to 1/3. The voltage is at 1.85v. It has an 850 core. I also have a 700 with an 800 core. I did a complete "hard mod" on it and did away with the GFD. It is at 1000MHz with the cache set at 1/3 also. The voltage is set on the Epox 7KXA mobo at 1.85v. Later I will hard mod the voltage on the Athlon. It all depends how the SiSoft Sandra burn in goes. I found the "Hard mod" help at Tomshardware.com. Good luck with yours.